The invention generally relates to an air bag, which in a broad sense is of annular or toroidal shape, which includes a means for filling its generally hollow center. The present invention also relates to air bag modules that incorporate the above air bag.
A typical driver side air bag module comprises a housing, an inflator, and an air bag and a cover. The housing is mounted at or near the hub or armature of the steering wheel. The inflator and air bag are located within the housing and the cover (and housing) protects the air bag. As the air bag inflates, the cover is separated permitting the inflating air bag to expand toward the occupant. There is a benefit to placing various informational related devices on or near the center of the cover as this region is easy to see and easy to reach by the occupant. As can be appreciated, because the cover is a sacrificial part of the module it is impractical to place permanent (and expensive) buttons, displays such as a GPS display, switches and the like on the cover. In addition, placing a hard display or switch on the cover may cause injury to the occupant in the event of a collision.
Another characteristic of the prior art construction is that on deployment, a relatively large, folded portion of the expanding air bag is initially thrust toward the occupant, which may increase the level of forceful interaction between the occupant and the expanding air bag. To restrict this forward motion of the air bag, many prior art systems have resorted to the use of tethers to control or limit the trajectory of the expanding air bag.
If a toroidal or annular air bag is used, this air bag would include a hollow center. An effective air bag would, however, incorporate a mechanism to fill the typically hollow center of this type of air bag. The present invention provides a simple, cost-effective, efficient solution.
It is an object of the present invention to provide an improved, generally toroidal or annular shaped air bag and to use same within a cooperating air bag module.
It is a further object of the present invention to provide an air bag module that can deploy about a fixedly positioned center or control module.
An advantage of using a fixed center module is that it can be used to support control or communication mechanisms and devices such as a horn switch, radio dials, cruise control buttons and even more complicated and expensive visual displays for a navigation system, including GPS satellite receiver display. These additional mechanisms and devices will be unaffected by the deployment of the air bag, which deploys about the center module. Additionally, after an accident, the air bag and cover will typically need to be replaced, however, there may be no need to repair or replace the center module.
Another object of the invention is to provide a cushion that initially fills radially before allowing a center core to collapse, filling the center portion of the cushion. In addition, the air bag cushion is encouraged to initially fill radially about the center control module due in part to the fixed center control module.
An added object of the present invention is to provide a driver side air bag having a slit or opening in a face panel thereof and to include within the bag a means for urging the slit toward a closed configuration as the air bag inflates, thereby inhibiting access to the center or hollow part of a generally annular air bag. It is also an object of the present invention to configure a center tubular portion of the air bag such that shortened sides of this tubular portion act as a tether to restrict the deployment of the air bag towards the occupant. The longer sides of the tubular portion provide additional fabric to fill in the center void (of the tubular portion) for occupant protection.
Accordingly the invention comprises: an air bag as well as an air bag module using the air bag wherein the air bag includes: a circular face panel having one of a slit or thin first opening generally at or near its center; a rear panel of substantially the same shape as the first panel and having a second opening, that is typically circular, the diameter of the second opening being sufficient to receive an inflator. The air bag further includes a tubular member element or portion having an open top and a closed bottom. The tubular member, element, or portion is secured to the face panel and located between the face and rear panels. The open top of the tubular member is secured about the first opening, such that access to the interior of the tubular member can be obtained through the first opening. As will be seen the walls and a bottom or closed end of the tubular member form a generally tubular cavity. A control module is first placed within the cavity, through the slit, and then fixedly secured to a steering wheel or the like with the face panel and in particular the first opening positioned radially about the control module. Upon inflation, the air bag deploys generally radially about the control module. As the air bag continues to inflate, pressure within the air bag acts on the top of the tubular member, proximate the first opening, tending to close the first opening (the slit) thereby preventing access to the fixed control modules through the generally tubular cavity.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.